Waterjet portioner machines are commonly used in the food industry for cutting products, such as chicken, beef, pork or fish. A high pressure stream of water can easily cut through meat products, without abrasives, at pressures from about 30,000 psi to over 80.000 psi. The jet of water (the “waterjet”) leaving the waterjet nozzle may be moving at about 4000 ft/second, or mach 3.5.
The waterjet streams are generated by pumping the water at the high pressure through a very fine diamond or ruby nozzle with an orifice diameter generally ranging from 0.004″ inches to 0.01 inches. Any remaining liquid portion of the water jet must be drained from the machine. However, not all the liquid remains as part of the water jet.
Rather, as the high pressure water jet stream leaves the orifice, it is generally coherent for a few inches, but it then begins to “break up” as the stream travels further from the orifice. As a result, mist is formed coming off the water jet stream, accompanied by sound waves. Moreover, when a water jet stream strikes a hard surface, it will break up completely into mist and droplets, wherein the droplets may be deflected at different angles into the interior of the machine depending on the angle of the hard surface they impact.
The mist in a waterjet portioner is unusual in that it can be a mixture of air, steam, and very fine droplets. The dynamics of this mix are very complex. The water under high pressure can be heated to high temperatures, such as one hundred and fifty degrees Fahrenheit to one hundred and eighty degrees Fahrenheit (150° F.-180° F.). Some of the heat can then be consumed in the rapid evaporation of water from enormous surface area of the droplets. The simultaneous mass and heat transfer of a non-standard fluid in rapid motion presents a difficult air handling problem for the evacuation and control of the mists. For instance, the mist from the water jet expands into a very large volume when it is generated, into an area of the machine that is generally enclosed for safety reasons. This large volume of mist that is continuously generated must be continuously evacuated from the enclosed area of the machines for a number of reasons.
One reason for continuous mist evacuation is that the mist would otherwise interfere with any vision/scanning system of the machine. In a water jet portioner machine, product is typically first carried past a vision/scanning system (which may have a light source(s) and a camera(s)), and then into the enclosed portioner housing where typically up to eight water jet cutters cut the product. Mist can migrate to areas where the vision system operates, interfering with the vision system's view of the product by either simply obscuring the view (i.e., the product cannot be seen by the camera(s) through the cloud of mist), or by condensing on the windows that protect the camera(s) and light source(s).
Another reason for continuous mist evacuation is that the visibility of the operators looking inside the cut housing can be severely limited by the mist. This makes troubleshooting of issues during production by operators and service personnel more difficult.
Additionally, mist can condense on the surfaces of the portioner housing above the product being conveyed, and drip onto the product, leading to hygiene concerns.
In seafood and poultry processing, it is not uncommon for the product to be in contact with water. For red meats and other products, there is much more emphases on keeping product dry. Water on red meat surfaces will promote browning of the meat surface due to oxidation. Additionally, there may be more strict regulations on labeling of water that is picked up by red meat than with poultry or seafood. Therefore, another reason for mist reduction and control is that it is especially important and beneficial for red meat processing.
Based on at least the foregoing, it can be appreciated that a mist management system and method thereof for a waterjet portioner or the like is desired. Such a mist management system and method may improve visibility into the machine, reduce condensation, minimize interference with the scanning system, and improve hygiene and processing efficiency, while remaining easy to clean, inspect and sanitize.